JPH076596B2 - Bearing lubrication device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horizontal shaft rotary machine, and more particularly to a bearing device in which lubricating oil is stored in a bearing box and a bearing is self-lubricated by rotation of a main shaft. .

[Conventional technology]

Conventionally, a lubrication device for sliding bearings such as electric motors on the horizontal axis has a self-cooling lubrication structure that naturally radiates heat with an oil ring lubrication method or a lubrication method using a viscous pump, etc., from the viewpoint of maintenance-free equipment and economical efficiency. There is. However, there is a problem that the oil ring system with a small amount of pumped oil cannot be applied because the required minimum amount of oil in the bearing must be increased significantly as the equipment speed increases.

Therefore, as a viscous pump oil supply structure that can be expected to greatly increase the amount of oil supply, Japanese Utility Model Laid-Open No. 61-198798 and Japanese Patent Application Laid-Open No. 62-151658.
Japanese publications and the like have been proposed.

Japanese Utility Model Laid-Open No. 61-198798 discloses a viscous pump structure in which an oil guide ring is provided on the outer periphery of a shaft collar formed on a main shaft, and the oil guide ring is fixed in a bearing housing. An oil guide ring that is made up of a circular ring plate and has a shape that sandwiches both axial side surfaces near the outer circumference of the bearing collar with concave legs and maintains a space between the concave bottom and the outer circumference of the opposite shaft collar. It has the structure provided. This method aims to increase the amount of oil supplied to the pump by enlarging the flow passage area surrounded by the oil guide ring and the shaft collar. However, during operation, the main shaft is heated due to bearing loss and other factors, causing thermal expansion of approximately several mm.
Therefore, the pump shape in which both sides of the rotary shaft collar are surrounded by the oil guide rings fixed to the housing cannot absorb the thermal expansion, which may impair the pump function.

Also, in general, the oil level is set as low as possible in consideration of agitation loss, and the guide ring and the majority of the side end surface of the shaft collar are installed in contact with the atmosphere. There was a problem that the air around it was entrained and bubbles were generated in the pump, degrading the performance of the viscous pump.
Further, in Japanese Patent Laid-Open No. 62-151658, a pump case is loosely fitted and mounted on the outer periphery and side end faces of a disk formed on a main shaft, and the pump case is movable only by rotation stop. It is a support structure. This system has a structure in which the pump case can follow the movement of the main shaft and absorbs the above thermal expansion, and the oil grooves formed on both sides of the pump chamber formed on the inner diameter surface of the pump case have a sealing effect. In addition, the concave legs exert an agitation preventing effect. However, in the case of increasing the amount of refueling, if it is expanded in the width direction, the increase of pump loss cannot be avoided, so it is not a good idea.
Moreover, the sealing effect cannot be obtained by simply opening the circumferential groove in the concave leg portion facing the side surface of the disk.

As described above, each of the publications has problems, and in order to expand the use range of the self-cooling self-lubricating structure, cooling is performed only by heat dissipation from self-convection from the tank surface. Therefore, there is a demand for a bearing lubrication device that increases the amount of lubrication and takes into account the loss reduction of each friction portion.

[Problems to be solved by the invention]

The prior art described above does not consider the shape effect of the seal mechanism and the oil suction part, which are the decisive factors in improving the performance of the viscous pump, and it is not possible to prevent bubbles from entering during operation of the pump. I couldn't get the performance.
In addition, the floating structure that does not fix the pump case not only invites abnormal air mixing due to one-sided inclination of the pump case, etc.
A fatal defect that stops the pump function may occur.

The present invention has been made in view of the above situation, and it is possible to supply appropriate lubricating oil to a bearing portion by a pump effect that is efficient from a low speed range to a high speed range without impairing the function of a viscous pump, which is reliable. An object of the present invention is to provide a bearing device for a horizontal shaft rotating machine that can be improved.

[Means for solving problems]

The purpose is to cover the outer periphery and side end surface of the oil disk fixed to the main shaft and to be loosely fitted and mounted with a predetermined gap,
A viscous pump that has a pump chamber on its inner peripheral surface that opens symmetrically in the circumferential direction from the lower end to the upper end over approximately half the circumference, has a discharge port at the upper end, and a suction port that opens below the oil level at the lower end. In the above, an arc groove having a diameter larger than the suction port diameter is formed in the upper end portion of the suction port over the axial direction, and a circumferential seal groove is formed inside the side covers arranged at both end portions of the pump case. In addition, a viscous pump with a sealing function is provided, in which an oil inlet is opened in the lower part and a stopper for closing the seal groove is provided in the upper part.

[Action]

When the rotating main shaft rotates, the lower part of the oil disk is always set below the oil level, so the suction port at the lower part of the pump case is also filled with lubricating oil, and when the oil disk rotates, the oil adhering to the surface Due to viscous friction action, it flows in the pump chamber in the direction of rotation, and the pressure is increased at the upper end stepped part.
Oil is supplied to the bearing from the discharge port through a circulation path such as a discharge pipe and an upper tank. On the other hand, the lubricating oil that has flowed in from the introduction port in the lower portion of the side cover flows in the circumferential groove due to the viscous frictional action of the side end surface of the oil disk as described above. The oil in this groove is boosted because it is stopped by the upper stopper, but the pressure in this portion is almost the same as the pressure in the pump chamber, so it is discharged to the outside from the slit portion on the side end surface.
By thus forming the curtain on the side surface of the pump by the oil film pressure, it is possible to prevent air from entering from the outside. Further, since the oil case is suspended on the oil disc, the inner peripheral surface of the pump case and the outer peripheral portion of the disk are in contact with each other in the upper part during the stop, while the lower part is in the non-contact state, but an oil film is formed with rotation. The pump case is movably held by an oil film. For this reason, the surface of the disk and the inner peripheral surface of the pump case are arranged so as to face each other with a slight gap, and even if the position of the suction portion and the disk are closest to each other, the suction groove has a circular arc groove to form a suction flow path. The suction resistance can be suppressed without breaking or by enlarging the flow path end portion.

Therefore, it is possible to exert an efficient pumping effect by preventing air from entering from the side surface of the pump case and making the flow of the suction part an easy shape effect.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In the figure, a rotating main shaft 1 of a horizontal axis rotating machine is supported by a vertically split sliding bearing 2, and the sliding bearing 2 is installed in a bearing box 4 via a bearing frame 3.
The lubricating oil 5 is stored so that the lower part of the bearing 2 is immersed. Labyrinth-type seals 6 are provided on the left and right side walls of the bearing box 4 to prevent the escape of lubricating oil.

Further, an oil disk 7 having a diameter larger than that of the journal portion is fixed to the rotating main shaft 1 near the side end of the bearing 2 and rotates together. A pump case 8 constituting a viscous pump is arranged on the outer peripheral portion of the oil disk 7, and side covers 9 are arranged on the side end surfaces thereof so as to face each other with a predetermined gap, and the oil surface (A) is the bearing 2 at rest. It is always set below the journal part and the lower bottom part of the oil disk 7 is immersed.

Further, as shown in FIG. 3, a pump chamber 11 is opened symmetrically in the circumferential direction from the lower end to the upper end in the circumferential direction on the surface of the inner land 10 of the pump case 8 at the lower end of the pump chamber 11. Is provided with an oil suction port 12 communicating with the lubricating oil, and an oil discharge port 13 for feeding the lubricating oil into the upper tank 19 through a discharge pipe 18 is provided at the upper end portion of the suction port 12. An arc groove 14 having a diameter larger than the suction port diameter is formed in the end portion in the axial direction.

Further, the side cover 9 is integrally fixed to both end surfaces of the pump case 8 with screws or the like, and a circular seal groove 15 is provided inside the side cover 9 so as to face the side end surface of the oil disk 7. An oil inlet is provided at the bottom of the seal groove 15
A stopper 17 is provided at the position corresponding to the terminal stepped portion of the pump case 8 on the upper portion of the pump case 8.

On the other hand, the lower half part of the bearing box 4 is an oil tank 4a for storing lubricating oil, and an oil guide 20 is arranged and fixed to the lower part of the pump case 8 and is connected to the oil suction port 12 by a suction pipe 21. At a position corresponding to, an elliptical through-hole 22 in the axial direction is opened larger than the outer diameter of the suction pipe 21 and is loosely inserted, so that the rotation is prevented and the axial movement due to the thrust force is not restricted. It is said.

In the above structure, the rotation of the rotating main shaft 1 causes a relative sliding motion between the outer peripheral surface of the oil disk 7 and the inner peripheral surface of the pump case 8, so that the lubricating oil with high viscosity has its viscous friction. The suction pipe 2 inside the pump chamber 11.
1. A pump action is performed in which the gas is sucked through the suction port 12 and discharged into the upper tank through the discharge port 13 and the discharge pipe 18. That is, as the disk 7 rotates in the direction of the arrow as shown in FIG.
As described above, the pressure is increased by the damming effect of the stepped portion between the end portion of the pump chamber 11 and the inner diameter land 10, and the pressure-increased fluid is discharged from the discharge port 13 and the discharge pipe 1 as indicated by arrow b.
8. The bearing 2 is filled with oil through the upper tank 19 and the lubrication inlet 23.

By the way, since the pump case 8 is suspended on the disk 7, the upper case is in contact with the disk when stationary and the lower part has a large gap. However, as the pump case 8 rotates, an oil film is formed on the upper land 10a, and the pump case 8 is Present in a floating state. Therefore, as shown in the fourth section, during operation, the disk 7 and the pump chamber 13 in the pump case 8 have a lower land 10b as shown by a chain line.
Even if it comes into contact with the suction port 12, an arc groove 14 is provided at the upper end portion of the suction port 12, and the groove is also filled with oil. It is possible to maintain smooth communication without doing.

On the other hand, as shown in FIGS. 2 and 3, the lubricating oil is sucked by the pump action as shown by the arrow (C) from the inlet port 16 at the lower part of the side cover 9 and flows in the circumferential seal groove 15 to move upward. However, the pressure is stopped by the upper stop 17 and the pressure is increased.
The pressure-increased lubricating oil is mixed into the pump chamber 13 due to the pressure difference, or is discharged into the atmosphere as shown by the arrow (d). In this way, the oil film whose pressure is constantly increased is formed in the seal groove 15, and it is possible to prevent air from entering from the end surface of the disk and side leakage from the pump chamber 13. Fig. 5 shows circular groove 14
It is experimentally found that a performance improvement of about 30% can be achieved by comparing the pump performance between the case where the seal grooves 15 are formed at both ends of the pump case 8 and the conventional method.

Moreover, since the pump case 8 is movably held, the pump case 8 is affected by moment load during operation or the pressure increasing force generated in the pump chamber, and in addition, vibrations become large due to the inclusion of bubbles, resulting in local contact or The pump function may be impaired if the axially unilaterally inclined state continues. However, since both ends of the oil disk 7 are provided with the sealing function as described above, both of them are contaminated with bubbles. There is nothing, and it is loaded with the fluid lubrication film.

Therefore, the pump case 8 can follow the operation of the disk 7 and maintain a normal pump action, so that the reliability of the device can be improved.

〔The invention's effect〕

As described above, the bearing lubrication device for a horizontal shaft rotating machine according to the present invention can improve the sealing effect by forming the pressure film on the end face of the suction port and the end face on the disk side. Without impairing the function, an appropriate pumping oil can be supplied to the bearing portion by the efficient pumping effect from the low speed region to the high speed region, and the reliability can be improved.

[Brief description of drawings]

1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a sectional view of a viscous pump according to the present invention, FIG. 3 is a perspective view of a viscous pump case shown in FIG. 2, and FIG. Fig. 5 is a partial performance diagram of the viscous pump, and Fig. 5 is a pump performance comparison diagram. 1 ... Rotating spindle, 2 ... Bearing, 4 ... Bearing box, 7 ... Oil disc, 8 ... Pump case, 9 ... Side cover, 10 ... Inner diameter land, 11 ... Pump chamber, 12 ... Suction port, 13 ... Discharge port, 14 ... Arc groove, 15 ... Seal groove, 16
…… Inlet, 17 …… Stopper, 22 …… Through hole.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiko Kawaike 502 Jinritsu-cho, Tsuchiura-shi, Ibaraki Hiritsu Manufacturing Co., Ltd. Mechanical Research Laboratory (72) Inventor Yuji Yamamoto 3-1-1, Saiwai-cho, Hitachi, Ibaraki Hitachi, Ltd. Hitachi factory (72) Inventor Hiroto Imai 2-9-1, Aize-cho, Hitachi-shi, Ibaraki Hitachi Service Engineering Co., Ltd.

Claims (1)

[Claims] 1. A bearing box, which has a bearing for supporting a rotating main shaft of a horizontal shaft rotating machine, stores lubricating oil so that a lower part of the bearing is immersed, and is divided into an upper half and a lower half, and the main shaft. The outer periphery of the oil disk fixed to the inner peripheral surface is loosely fitted to the inner peripheral surface through a predetermined gap, and a pump chamber is formed on the loose fitting surface from the lower end to the upper end in the circumferential direction for almost half the circumference. A bearing device having an oil supply means that circulates a lubricating oil by a viscous pump that has a suction port opened at its lower end and that has a pump case configured so that the suction port is always below the oil level, A circular arc groove having a diameter larger than the suction port diameter is formed in the upper end of the suction port in the axial direction, and a circular seal groove is formed in the vicinity of the outer peripheral portion on the side in contact with both end faces of the pump case. Open the oil inlet below the oil surface at the bottom of the groove and seal it at the top. Bearing device of the horizontal axis rotary machine, characterized in that a guard wall damming the.